This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A270970 #11 Mar 30 2016 04:39:14
%S A270970 1,2,4,5,6,8,9,11,14,16,17,21,22,24,28,31,32,37,38,53,56,57,58,71,72,
%T A270970 73,77,85,86,131,132,138,141,142,143,163,164,165,167,289,290,310,311,
%U A270970 316,403,404,405,454,455,458,460,463,464,478,479,557,559,560,561
%N A270970 Number of subsets of {1,...,n} with sum of elements equal to least common multiple of elements.
%C A270970 Similar to A270875 but also counts singletons, the trivial solutions.
%H A270970 Hiroaki Yamanouchi, <a href="/A270970/b270970.txt">Table of n, a(n) for n = 1..200</a>
%F A270970 a(n) = A270875(n) + n.
%t A270970 Table[Length@ Select[Rest@ Subsets@ Range@ n, Total@ # == LCM @@ # &], {n, 22}] (* _Michael De Vlieger_, Mar 27 2016 *)
%o A270970 (PARI) a(n) = {nb = 0; S = vector(n, k, k); for (i = 0, 2^n - 1, ss = vecextract(S, i); if (sum(k=1, #ss, ss[k]) == lcm(ss), nb++);); nb;}
%Y A270970 Cf. A084422, A270875.
%K A270970 nonn
%O A270970 1,2
%A A270970 _Michel Marcus_, Mar 27 2016
%E A270970 a(31)-a(58) from _Hiroaki Yamanouchi_, Mar 30 2016